1. Field of the Invention
The present invention generally relates to an observation apparatus and a method for manufacturing an electronic device and more particularly to an observation apparatus and a method for manufacturing an electronic device in which an underfill resin is disposed on an electronic component.
2. Description of the Related Art
There has been known flip-chip mounting as a method for mounting an electronic component such as a semiconductor chip (hereafter referred to as a chip component) on a mounting substrate. The flip-chip mounting method is for forming a gold (Au) bump on an electrode of a chip component and connecting the chip face down to the mounting substrate. In the flip-chip mounting method, underfill resin (resin bond) is filled between the chip component and the substrate so as to reinforce the connection between the Au bump and the electrode.
Preferably, the underfill resin is filled in a connection space in a uniform manner. However, a void (air gap) may be generated in the underfill resin during a step of coating the underfill resin or a step of mounting the chip. This affects connection strength and quality. In view of this there have been various methods for detecting the void generated in the underfill resin (refer to Patent Documents 1 and 2)
Patent Document 1: Japanese Laid-Open Patent Application No. 64-025045
Patent Document 2: Japanese Laid-Open Patent Application No. 09-196617
However, the conventional methods disclosed in Patent Documents 1 and 2 are for examining the presence of the void through observation of X-ray transmission and a cross section of mounting after the chip is mounted. Thus, the conventional method is capable of detecting the presence of the generated void and a position thereof after the chip is mounted. However, this method poses a problem in that the method is not capable of observing how the void is generated, so that a cause of the generation of the void remains unclear and it is not possible to determine conditions of steps of the flip-chip mounting so as to control the generation of the void.